<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Word 14 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoPlainText, li.MsoPlainText, div.MsoPlainText
{mso-style-priority:99;
mso-style-link:"Plain Text Char";
margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
span.PlainTextChar
{mso-style-name:"Plain Text Char";
mso-style-priority:99;
mso-style-link:"Plain Text";
font-family:"Calibri","sans-serif";}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:70.85pt 2.0cm 70.85pt 2.0cm;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="FI" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoPlainText"><span lang="EN-US">Hi all,<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">I have an annoying problem.<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">I have a pretty much direct pipeline from a camera feed to the screen:<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">gst-launch-0.10 v4l2src ! 'video/x-raw-yuv,width=640,height=480,framerate=30/1' ! ffmpegcolorspace ! ximagesink<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">This gives me a pipeline v4l2src -> capsfilter -> ffmpegcsp -> ximagesink . No forking paths or threads or queues here.<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">I’ve added some code that sends a custom serialized downstream event in v4l2src, right after it has pushed the buffer downstream.<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">I would expect the event be received in ximagesink after the buffer has been received; after all, that’s what I think ‘serialized’ means.<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">However, the custom event passes through all the elements in the pipeline without stopping anywhere; the buffers follows through in his own steady pace.<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">Why does this happen? Is it because my pipeline is too simple to be serialized? Is it because there's practically no synchronization anywhere in the pipeline (the data never needs to wait for some other buffer to be
synchronized) ? Can I solve this problem by adding some synchronizing element in the pipeline?<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Thanks,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">JP Ikaheimonen | SW Development Engineer </span>
<a href="http://go.mentor.com/sourceryanalyzer"><span lang="EN-US" style="color:blue">http://go.mentor.com/sourceryanalyzer</span></a><span lang="EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Mentor Embedded(tm) | Nucleus(r) | Linux(r) | Android(tm) | Services | UI | Multi-OS<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Android is a trademark of Google Inc. Use of this trademark is subject to Google Permissions.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Linux is the registered trademark of Linus Torvalds in the U.S. and other countries.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
</div>
</body>
</html>